rocketgym 0.0.13

OpenAI Gym for vertical rocket landing. Features full 2D physics engine and works like any other gym.

Rocket Landing Gym

Open AI Gym for vertical rocket landing containing an extensive tool to incorporate curriculum learning for your agents.

Installation

pip install rocketgym

Minimal usage

from rocketgym.environment import Environment
import random

env = Environment()
observation = env.reset()
done = False

while not done:
    observation, reward, done, info = env.step(random.randint(0, 3))
    env.render()

Environment

Rocket

Rocket is treated as a 2D free body. Its physics properties have been modeled after Falcon 9. By default rocket is spawned

State space

1. Angle made with y-axis ($rad$): [$-\frac{\pi}{2},\frac{\pi}{2}$]
2. Position Y ($m$): $[0,\infty]$
3. Velocity X ($\frac{m}{s}$): $[-\infty,\infty]$
4. Velocity Y ($\frac{m}{s}$): $[-\infty,\infty]$
5. Angular velocity ($\frac{rad}{s}$): $[-\infty,\infty]$

Action space

At each timestep, rocket can perform one of the four actions:

1. Left - rotate the engine to the left and set maximum thrust
2. Mid - rotate the engine to the middle and set maximum thrust
3. Right - rotate the engine to the right and set maximum thrust
4. None - turn off thrust

Reward

Reward function takes multiple components into consideration:

1. For each second, agent looses $0.3$.
2. For impact with the ground, agent receives $15$.
3. At impact, agent looses $0.5$ for each $rad$ off the vertical axis.
4. At impact, agent looses $0.25$ for each $\frac{rad}{s}$ of angular velocity
5. At impact, agent looses $1$ for each $\frac{m}{s}$ away from $-1\frac{m}{s}$ vertical velocity
6. At impact, agent looses $0.25$ for each $\frac{m}{s}$ of horizontal velocity

Curriculum Learning

The best part about this gym. It allows you to alter the difficulty of the environment by changing things like initial height, action space etc.

Spawn height

from rocketgym.environment import Environment

env = Environment()
env.curriculum.set_fixed_height()
env.curriculum.set_random_height(1,5)

env.curriculum.enable_random_height()
env.curriculum.disable_random_height()

env.curriculum.enable_increasing_height(rate=0.05)
env.curriculum.disable_increasing_height()

Spawn orientation

env.curriculum.enable_random_starting_rotation()
env.curriculum.disable_random_starting_rotation()

Altering the reward function

env.curriculum.enable_x_velocity_reward()
env.curriculum.disable_x_velocity_reward()

Dashboard

This module enables saving flight logs. Logs will be saved in logs/plots directory.

Sample usage

from rocketgym.dashboard import Dashboard

# Creating logger
dash = Dashboard()

# Saving flight log
dash.plot_log(env.rocket.flight_log, episode=0)